Fundamental burnishing characteristics of Ni-based alloy using coated carbide tool

Abstract The fundamental characteristics of a developed burnishing process targeting an Ni-based alloy were investigated. A spherical burnishing tool, which was coated using diamond-like-carbon material, was rotated at a high speed and inclined from the normal direction of the target surface to obtain a sliding effect during the developed burnishing process. The Ni-based alloy, which was conducted the solution treatment and surface finishing with a file, was used as a workpiece. The burnished surface was evaluated by its roughness, profile, subsurface microstructure, and mechanical properties such as hardness and solid particle impact strength. The surface roughness was considerably improved because of the burnishing process, and the influence of thrust force on the roughness of the burnished surface was observed. In addition, the burnished surface appeared as a clear mirror. The difference in the subsurface microstructure between the preliminary and burnished surfaces was observed within a 20 μm depth from the surface, and the surface hardness was increased by the burnishing process. The difference in erosion rate between the preliminary and burnished surfaces was also observed within a 20 μm eroded depth, and the superiority of the developed burnishing process for an Ni-based alloy was experimentally verified.